<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>{{ str }}</h1>
<h1>{{ str | length}}</h1>
<h1>{{ name | default:"默认名字" }}</h1>
<h1>{{ html }}</h1>
<h1>{{ html | safe }}</h1>
<h1>{{ date }}</h1>
<h1>{{ date | date:"Y-m-d" }}</h1>
</body>
</html>